Preheat oven to 180°C.
Sift together the flour, baking powder and cocoa into a large mixing bowl.
Add the caster sugar and mix lightly to combine.
In a separate bowl whisk together the egg, buttermilk, melted butter and vanilla extract until well combined.
Fold the wet ingredients into the dry ingredients until just combined, then stir in the whisky.
Pour into 4 individual, greased ovenproof ramekins and set aside.
For the topping: Mix together the cocoa and sugar and sprinkle evenly over each pudding.
Pour 80ml of boiling water over each individual pudding and bake in oven for about 20-25 minutes or until the surface has risen and is crisp.
Remove from oven and serve immediately with thick cream or ice-cream.
There should be a thick and glossy chocolate sauce at the bottom of the dark chocolate sponge.